Rotary brush



I. A. EPPSTEIN Aug. 7, 1934.

ROTARY BRUSH Filed June 21, 1934 Patented Aug. 7, 1934 Isadore A. Eppstein, Toledo, Ohio Application June 21, 1934, Serial No. 731,736

1 Claim.

This invention relates to motor driven rotary brushes, and has for its primary object the provision of a small compact brush of this character adapted for dental use and having a motor 3.: of the electric vibrator type mounted in the han- 5 die thereof.

The invention is fully described in the following specification, and one embodiment thereof illustrated in the accompanying drawing, in

which- Figure l is a side elevation of a device embodying the invention, with parts in central longitudinal section; Fig. 2 is a view on the line 22 in Fig. 1, with parts in section; Fig. 3 is an enlarged elevation of the motor and carrying frame shown in Fig. 1; Fig. 4 is an enlarged side elevation of one of the brush guards; Fig. 5 is an elevation of the vibrator arm with some of the associated parts; Fig. 6 is a perspective view of the carrying frame for the motor; Fig. 7 is a section on the line 7-7 in Fig. 1; and Fig. 8 is a diagrammatical illustration of the motor wiring.

Referring to the drawing, 1 designates a casing of suitable form to provide a handle for the operator to grasp and having the tubular extensions 2, 2 projecting in axially opposed relation from opposite sides thereof near one end, as shown. The casing 1 comprises twosections secured together, in the present instance, along a longitudinal center line, and forms a chamber 3 in which the operating motor is mounted. The extensions 2 have shaft sections or spindles 4 mounted therein with their outer ends projecting from the ends of the extensions and each ss adapted to have a brush 5 detachably secured thereto to facilitate easy removal and replacement.

The shaft sections 4 are axially alined and connected to, or form extensions of, the respective ends of a cross shaft 6 journaled in a frame 7 suitably mounted in the casing 1. Each extension 2 is provided at its outer end with a detachable guard 8, which extends around substantially half of the brush and prevents contact of the brush with the tongue or checks when in use. The frame 7 is substantially of U-form, and in addition to forming a bearing for the shaft 6, carries the frame 9 of the motor, such motor frame being mounted at its lower end between the free ends of the leg members of the frame 7. The frame 9 carries the customary vibrator coils 10, 10, between which the vibrator arm 11 is mounted for oscillating movements, being pivoted to the frame 9 at 12 and having its other end forked or lonb gitudinally slotted and receiving the crank 13 of a crank shaft 14. This shaft is mounted in suitable journals provided in the frame 9 and has one end projecting without the adjacent side of the frame 7 through an opening '7 therein and has its other end carrying a suitable balance wheel 15 and pinion 16. This pinion is in driving mesh with a gear 17 mounted on the shaft 6 so that rotation is imparted to: such shaft from the turning of the crank shaft 14. It is apparent that as the circuit through the coils 10 is alternately 65. made and broken, the vibrator arm 11 is first attracted to one and then to the other of the coils, thus imparting oscillations thereto, the speed of which depends upon the speed of making and breaking of the coil circuit, and this movement of the arm imparts a rapid rotation to the crank shaft. The speed of rotation of the shaft 6 is materially reduced from that of the crank shaft 4, due to the speed reduction gearing connecting the same.

The end of the crank shaft 14, which projects without the frame 7, has one side cut away to provide a cam surface 18 and this turns between two spring contact fingers 19, 19, (Fig. 7) in engagement with insulating surfaces 20 thereon, so and as the shaft rotates, causes such fingers to alternately make and break engagement with the respective contact 21. A control button 22, which is slidable lengthwise of the casing 1 has a part 23 adapted to be moved into engagement with 35 the insulating part 20 of the finger 19, which has its contact closed, and to hold such finger in open position, and is also movable to withdraw the part 23 from such engagement with the contact finger to permit a starting and running of 9b the motor. The lead wires for the motor may extend through an opening 24 provided in the outer end of the casing 1.

The purpose of providing the device with two shaft extensions 4 and brushes is to enable either 95. brush to be used, depending on the direction of turning desired for cleaning the teeth. This prevents the necessity of providing a reversing means for the brush driving shaft and thereby materially simplifies the device.

It is found in practice that a small vibrator motor can be employed, thus requiring very little space in the handle, and that it very effectively operates to impart the requisite rotation to the brush shaft. If desired in practice to use only one brush-carrying shaft, the one extension 2, the right-hand one in the present instance, and its associated shaft section 4, may be removed from the casing 1, provision being made for disconnecting and removing these parts.

handle extension and adapted to carry an abrading element at its outer end, an electric vibrator motor carried by said frame within the handle including a vibrator element disposed lengthwise of the handle and pivoted adjacent one end and having a longitudinal slot adjacent the other end, a shaft having a crank slidably embraced by said slot and driven by vibrating movements of said element, and a driving connection between the motor crank shaft and the first mentioned shaft.

ISADORE A. EPPSTEIN. 

